The progression of many dilapidating diseases such as cancer, rheumatoid arthritis and cardiovascular disease are characterised by the involvement of several subclasses of the metalloendoproteinase superfamily termed metzincins (1, 2). Both MMPs (matrix metalloproteinases-subclass matrixins) and ADAMs (a disintegrin and metalloprotease-subclass reprolysins) have an established role in cancer progression, the retinopathies and inflammatory pathologies such as inflammatory bowel disease, arthritis and Crohn's. Other metzincins including the meprins are associated with renal and urinary tract pathologies and the pappalysins with pregnancy-related hypertensive disorders (see below). Accordingly, there is a need for methods and compositions for determining levels of different metzincins in a biological sample and to inhibit therapeutically the catalytic activity of particular metzincins associated with the progression of the above mentioned pathologies.